LoST: A Protocol for Mapping Geographic Locations to Public Safety Answering Points
Public Safety Answering Points (PSAPs) serve limited geographic areas, so emergency callers must be directed to the most appropriate PSAP. As part of the overall Internet Engineering Task Force (IETF) emergency services architecture, the authors have developed a new protocol, LoST (Location-to-Service Translation), that allows end systems and VoIP proxies to map location data into URLs representing either PSAPs or other SIP proxies that perform a more fine-grained mapping. LoST is designed to operate globally, with a highly-distributed authority. They describe the protocol and its design rationale.